London Marathon runner was left in coma after drinking too much water

A London Marathon runner was left in a coma after drinking too much water during the race.

Johanna Pakenham, 53, drank more than a dozen bottles of water to try and cope with the heat, and has no recollection of crossing the finish line.

The mother-of-four later suffered a seizure at home, with her partner being forced to perform CPR to keep her alive until the ambulance arrived.

Ms Pakenham, from Wadwick, Hampshire, drank so water her sodium levels became abnormally low in a life-threatening condition know as hyponatremia.

According to The Met Office, the latest London Marathon was the hottest on record, hitting highs of of 23.2 C.

Now fully recovered, Ms Pakenham is speaking out to raise awareness of the dangers of drinking too much water while running.

Johanna Pakenham was left fighting for her life in a coma after drinking too much water during the London Marathon. This caused her to suffer from abnormally low sodium levels

After suffering a seizure at home, her partner performed CPR until an ambulance arrived

Ms Pakenham (centre) has little memory of taking photos during the race or finishing it

‘There is such a thing as too much water’

Ms Pakenham said: ‘I love running and I’ve been doing it for years. I’ve taken part in four marathons, although this was my first one in 15 years.

‘I remember starting the race but around half way through is when things start to get hazy.

‘I saw my family at the beginning and apparently, I saw them three times throughout, but I have no recollection of that.

‘I remember my dad’s voice in my head saying “make sure you stay hydrated” but without the electrolytes, the water was doing more harm and making me worse, there is such a thing as too much water, which I learnt.’

‘I have no recollection of it’

Ms Pakenham believes she drank a small bottle of water at around 20 stations along the route but was not replenishing the electrolytes she lost with ‘energy’ drinks.

She said: ‘I had about 400 metres to go and I remember saying “I’m wobbly” and my family couldn’t believe I wasn’t going to cross that finish line.

‘There’s a picture of me taken at the starting line and I look fine, then I had a photo taken at the finish line, I have no recollection of it being taken.

‘I don’t recognise that woman in that photo.’

Ms Pakenham (right) started to feel ‘wobbly’ after stopping at 20 water stations on the route

She saw her family three times throughout the race but has no recollection of any of them